In Study On Nutrient Content,in Vitro Digestion And Gas Production Characteristics Of Main Plants In Inner Mongolia Desert Steppe

The main thirteen plants were collected in the growing period of forage in Xilamuren grassland of Inner Mongolia from June to September,2017.The nutrient content,in vitro digestibility,total gas production and CH4 concentrations and its 813C value were measured on species and functional groups.The correlation between components was analyzed to provide reference for grazing livestock management.The main results were shown as follows:1.The crude protein content and in vitro digestibility decreased gradually,and the contents of crude fiber and crude ash increased with the increase of grass maturity.The energy values of each life form were as follows:perennial grasses,perennial forbs,shrubs semi-shrubs,annuals and biennials plants.2.The total gas production after digestion of simulated ruminants increased with the fermentation time,but the fermentation rate decreased with the increase of time.The total gas production of 48 h digestion was as follows:perennial miscellaneous grass,shrub,semi-shrub,perennial grass,biennial plants.3.After fermentation simulation,CH4 concentration increased with the increase of months,but the increasing extent of each life form was different.The difference of ?13C value of CH4 in different plants was larger,and leguminous plants were obviously smaller than Gramineae,Compositae and Labiatae families and genera.The CH4 production of forage varied from month to month.4.There was a correlation with the conventional nutrients,digestibility,energy value and the total gas production of forage after digestion and degradation of simulated ruminants(P<0.05).Gas production was negatively correlated with crude protein,digestibility and energy,while is positively correlated with acid detergent fiber.Forage energy was negatively correlated with neutral detergent fiber(P<0.01).